1. Field of The Invention
The present invention relates to a device in a building sturcture, especially for supporting structures which by varying load are subjected to deformation.
2. Description of The Prior Art
In connection with large roof stuctures, especially in connection with corbel trees, frame works and suspended roofs, the deformation from the loads may be so large that problems are created for adjacent stuctures, for example walls and gates. Heavily influenced are large sliding gates for hangars, workshops etc. The net weight loads render permanent deformation of the foundation with the underlying loose earth masses or rock, columns, main beams and secondary systems, whereas snow and wind render variable deformations.
In connection with sliding gates for hangars, workshops etc., these have accordingly to be designed in such a manner that jamming is avoided at extremely large loads, a fact which involves a complicated and expensive gate structure and/or costly overdimensioning of the supporting stuctures.
In stuctures having large spans and tall supporting stuctures rendering large non-useable volumes, the necessary heated air volume in such buildings represents an economic factor in pace with increasing energy prices. If the building comprises large gates which are frequently opened, this will entail a total air exchange at frequent intervals, which renders large energy losses and a large and costly heating arrangement for raising the room temperature quickly to a level at which the work activity can proceed.
Further, for the achievement of rational building of hangars and industrial buildings etc., comprising large free spans, great emphasize is laid on quick delivery and assembly of the elements involved in the structure. At the same time, the building should be easy to demount or move.
The prior art known from German Patent DE PS 448.790 relates to a joint splitting of a building for absorbing relative movement within the structure. In other words, here is tought a passive system rendering a pure control of undesired forces, but the system does not give any instructions for a controllable deformation, let alone active displacement elements included as an "integrated" part of the structure.
From German Patent DE PS 395.082,there is known a hydraulic system which by its inertia transfers rapidly applied loads, but which by long time loading produces a permanent deformation of the structure, for example if a larger train should remain on the bridge. The hydraulic system which is included in the prior art building structures, especially bridges and corresponding edifices, is composed of passive elements which to a certain degree monitor unwanted forces, but any form for active displacement for compensating any deformations is not at all the teaching of this prior art technique.
EP-application No. 20770 relates to a method for constructing a space frame work of steel comprising standardized rods. The mounting together takes place substantially on the ground. The structure is raised to its correct height by means of lifting devices, and is given its final form by means of adjustable joints. Thereafter, roof plates are put in position, and no displacement of the structure takes place in the finished building.